The debt that never ends
Credit card debt is the most expensive borrowing most households ever do, with rates commonly north of 20% APR. But what really traps people isn't the size of the rate: it's an arithmetic detail almost nobody notices until they're already inside it.
1. Paying every month… and never finishing
You owe $5,000 on a card at 22% APR. You get organized and start paying $85 every month, religiously, without using the card again. How many months until it's paid off?
2. The turning point
Drag what you pay each month. There's an invisible line — the month's interest charge. Below it, the balance grows no matter how much you pay. Just above it, you do pay it off, but it takes decades. A little higher, and the timeline collapses. It's the same amortization math as a mortgage, only working against you.
Chart of the outstanding balance over time for the chosen monthly payment.
3. What protects you (and what doesn't)
Since the CARD Act of 2009, every US statement must carry a "minimum payment warning" box showing how long the debt takes to clear if you pay only the minimum, and what it would cost to clear it in three years. It's worth reading — it exists precisely because the numbers are so counterintuitive.
But disclosure isn't protection: there is no federal cap on credit card interest rates. What actually works is leaving the high rate behind: call and ask for a lower APR (issuers grant it more often than people expect), look at a 0% balance transfer if you qualify — counting the transfer fee — or a lower-rate personal loan, and always attack the highest-rate balance first.
Before accepting any payment plan, compare the rate, not the monthly payment — a small payment over a long term is usually the most expensive option. And remember the invisible line: any payment below the month's interest reduces nothing. If you can't cover the interest, paying on time won't fix it — that situation needs the contract renegotiated.
Plan your payoff
See exactly how long your balance takes and how much each extra dollar per month saves.
Open the Credit Card Payoff Calculator →See also: Compound interest · Loan · Lesson: the 8th wonder of the world
Sources: Credit CARD Act of 2009 (minimum payment disclosure requirement). Teaching simulation — your card's terms, fees and how interest is compounded may differ. Not financial advice.